1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
|
#include "fast_float/fast_float.h"
#include <cassert>
#include <cmath>
#include <cstdio>
#include <ios>
#include <iostream>
#include <limits>
#include <string>
#include <system_error>
template <typename T> char *to_string(T d, char *buffer) {
auto written = std::snprintf(buffer, 64, "%.*e",
std::numeric_limits<T>::max_digits10 - 1, d);
return buffer + written;
}
bool basic_test_64bit(std::string vals, double val) {
double result_value;
auto result = fast_float::from_chars(vals.data(), vals.data() + vals.size(),
result_value);
if (result.ec != std::errc() && result.ec != std::errc::result_out_of_range) {
std::cerr << " I could not parse " << vals << std::endl;
return false;
}
if (std::isnan(val)) {
if (!std::isnan(result_value)) {
std::cerr << vals << std::endl;
std::cerr << "not nan" << result_value << std::endl;
return false;
}
} else if (copysign(1, result_value) != copysign(1, val)) {
std::cerr << "I got " << std::hexfloat << result_value
<< " but I was expecting " << val << std::endl;
return false;
} else if (result_value != val) {
std::cerr << vals << std::endl;
std::cerr << "I got " << std::hexfloat << result_value
<< " but I was expecting " << val << std::endl;
std::cerr << std::dec;
std::cerr << "string: " << vals << std::endl;
return false;
}
return true;
}
void all_32bit_values() {
char buffer[64];
for (uint64_t w = 0; w <= 0xFFFFFFFF; w++) {
float v32;
if ((w % 1048576) == 0) {
std::cout << ".";
std::cout.flush();
}
uint32_t word = uint32_t(w);
memcpy(&v32, &word, sizeof(v32));
double v = v32;
{
char const *string_end = to_string(v, buffer);
std::string s(buffer, size_t(string_end - buffer));
if (!basic_test_64bit(s, v)) {
return;
}
}
}
std::cout << std::endl;
}
int main() {
all_32bit_values();
std::cout << std::endl;
std::cout << "all ok" << std::endl;
return EXIT_SUCCESS;
}
|
